save_typeahead(). typedef struct
{
typebuf_T save_typebuf;
int typebuf_valid; // TRUE when save_typebuf valid
int old_char;
int old_mod_mask;
buffheader_T save_readbuf1;
buffheader_T save_readbuf2;
#ifdef USE_INPUT_BUF
char_u *save_inputbuf;
#endif
} tasave_T;